Automatic drain device for cooling systems



Sept. 24, 1946. G. wool: l AUTOMATIC DRAIN DEVICE Fon cQoLIG sYsTEu 2 Sheets-Sheet l Filed oef. 25, 1944v sept. 24, 1946. G. waan* 2,408,183

UTOMATIC DRAIN1 DEVICE FOR COOLING SYSTEM c Patented Sept. 24, 1,946

UNITED `STATES 4PA'EIW.' OFFICE W 2,408,133r l AUTOMATIC DRAIN COOLING SYSTEMS n n -George'WoocL Toronto, Ontario, Canada. Application October 25, 1944, Serial No. 560,324

(Cl. 12s-174) j 5 Claims. 1

The invention relates to improvements in engine warming devices as described in the present 'specification and shown in. the accompanying drawings that form a part of the same. 4

The objects of the invention are tol provide simple and eicient means whereby the water,

and oil, used in .the cooling and lubricating systems of an internal combustion engine may be remainingat, or near, for a long periodof time at which time it may be quickly returned to the n engine in a heated statefwhereby to instantaneouslyheatthelengine block and insure easyV startingj to'eliminateV the necessityl of usingy antifreeze and thereby avoiding the corrosion Vof metal and damage to parts usually occasioned by its use; to provide efficient means for forcing the liquid to andfrom thefauxiliary tank regardless of the position of such tank in relation to the engine and radiator, to provide a device of the type specied which will operate automatically uponthe turning of the ignition switch, thereby eliminating all danger of damage to theeng'ine parts such as might be occasioned werethefen- 'gine kept in operation after the liquid had been removed from the cooling system and generally gg,

to vprovide a device for ,the ,purpose specified which -will be simple and inexpensiveto construct, easy to install, efficient in operation and in connection with which there will be no operating cost.

With the above and other obit-:cts'inxview the invention consists in the novel features olfr con'- struction, arrangements and combinations of parts described in the present specication and more particularly pointed outin theclaims for novelty following.

In describing the iin/entier;y reference willbe made to the accompanyingdrawings, in which: Figure l isa side. elevation of an automobile engine and'cooling system showing the invention the air compressing member regardless of the condition of the outsideatmos- `phere, the temperature obtaining at theftime of insertionfinto the tank. f

The tank maybe oflan'yk desired shape to Conveniently fit lbeneath the hood of an automobile engine, andy is shown herein. positioned above the engine block near' thelevel of the top ofthe radiator 4, but as will be apparent from the ensuing description it may be placed in any desired location, and saidtank may be supported in any desired manner, such as by the employment of brackets 5. ,f

. In order to accommodate both the oil and the water, `or other cooling liquid, the tank A is preferably divided by a vertical partition Sinto two yseparate compartments 1 and 8 respectively, one compartment, ,herein shown as '1, preferably being the largerof the twov to hold` the water used in the cooling system and the other and smaller f compartment 8 being forthereceptionof the oil vfrom the crank case.

The'tank is provided with an opening lSiinthe bottom thereof -to. permit of `.the passage of the waterk from thecooling vsystem to the interior of the water compartmenty 1f of the auxiliary tank. Avalve casing l0 is secured in any-desired manner to the under side of the tank A with the outlet opening [l thereof in register with Athe inlet Elin` saidy tank rwhereby the water may, flow into and out of the water compartment 1.

The valve casing l0 is provided with a vertical water passage Illa extending, completely through same rand hasanv inlet opening I2 in the bottom and said'casingis also provided with a centrally vdisposed vertical deflecting member I3 posi-v` tionedbetween the inlet andoutletopeningsand spacedV at its ends Vfrom the top and bottom walls of the casing whereby to provide .two distinct passagesior ,the water, the one passage Ila beingemployed in the transfer of the Water to the auxiliary tank andthe other, Illa, to be used in the transfer ofthe water from the said auxiliary tank, the route being pre-determined by the position of the valve, Aas Will be describedrin detail hereinafter, k u r c f l "The valve casing l0 is provided with opposed 3 centrally disposed horizontal extensions I4 and I5 respectively, both of which are bored to receive a horizontally operable valve I6 which extends through the deflecting wall I3 and both being closed at their ends.

The extension I4 of the valve casing II) may be of even bore throughout its length while the extension I5 is enlarged interiorly for a portion of its length near its outer end for the vreception of a solenoid coil I8, the purpose of which latter will be set out in detail hereinafter.

The valve I6 which is slidably supported in thev bores of the extension I4 and the deecting wall I3 and in the bore of the portion I-S of theextension I5 has a circumferential cut 29 therein near the end of the portion which issupported-within the extension I4, adapted in the oneposition of the valve to register with the passage- Illa-whereby to provide a passage for the water-fromthe auxiliary tank A and said valve also has another circumferential cut 2l adapted in another posivtion of the valve to register withy the passage I la whereby to provide a passage around the Wall I3 forthe water from the inlet I2 -in progress tothe said auxiliary tank.

The valve I6 is preferably of such length that when it is ldrawn to its fullest extent into the extension I4 vit will project into'the reduced inner end vof the extension I5 just far enough to -be properly supported by the wall of the said reduced portion of said extension'll5. `The valve is provided with a stem 22 extending 4a distance into the extension I5 andsuch stem is provided with an enlargement, or head, `2 3 terminating shortof the-closed end of said extension a suincient distance to permit ofthe proper reciproca- `-tory movement of said valve within the casing.

The valve I5 is normally held ,fully projected "intmthe extension ,I4 by means of -a coil spring 24 encircling the stem 22 and confined between the end of the body of the valve and a flange 25 secured within the enlarged portion of the eX- tension l5.

It willbe obvious that when thegvalve I6 is in lthe position shown in Figure 2 the passage to the auxiliary tank -will be open Vand the vertical outlet passage will bey closed and 'when-the valve -is withdrawn fully against the pressure of the coil spring 2,4 the vertical outlet passage from the auxiliary tank will be open and the -inlet closed and further that when the valve is in its intermediate Vposition both said passages will be closed by thevcentral body of the valve.

A ball 2l seating on an annulargshoulder 21a formed on the wall ofthe passage Ila serves to close Vthe said passage against the escape of water from the auxiliary tank.

' The'valve housing is provided with a Isuitable opening .21D in the bottom thereof adapted to'be closed by a screw plug 2Ic.

A pipe .28 leading from the lower end of the radiator andregistering with the inlet kI2 in the valve casing I provides a passage for the liquid in thedraining and filling of the radiator and engine.

Y29 is the 'iioat control unit mounted on the top of the auxiliary tank over a suitableopening 3i) in said tank and having a suitable gasket seal 3l?. This float unit carries a bracket "3.2 to the lower end of which is lpivoted one end of a float arm v33 which extends into the water compartment 'I andrcarries on its free end a float 34.

:The member 29 is `provided with an outlet ,3.5 communicating by means of a pipe 36 with the interior of the intake manifold ofthe engine for CFI 4 the purpose of providing a suction for exhausting the air from the interior of the liquid compartment and drawing the water into said compartment.

A valve 37 positioned within the outlet 35 to the suction pipe 38 and seating on a suitable seat within said outlet provides means for opening and closing the entrance to said pipe 36.

The valve 3.1 is provided .with a stem 38 and the lower end of the stem is pivotally connected by means of an arm 39 with the bracket 32. This arm 39 is connected intermediate of its length with the float arm 33, at a point removed from the Vpivotal-point of the latter, by means of -a 'rod 49, whereby movement of the float arm due to the rise of the liquid in the compartment 'I will cause simultaneous movement of the valve 3l intovengagement with its seat and thus shut off the vacuum from the intake manifold upon completion of the entry of the liquid into the tank A and whereby downward movement of the float will cause the valve to move from its seat and admit of the operation ofthe vacuum upon the emptying of the tank.

A spring 4I connected at one end to the arm 39 near its outer end and at its other end to the bracket 32 tends to accentuate the .movement of the said. arm 3S in its lup or down movement.

42 is an air vent extending through the member 29 and having a valve '43 seating on a shoulder or seat therein, said valve having its stem -44 pivoted to the arm 39 whereby oncompletion of the upward lmovement of the float arm 33 said valve will have movedaway from its .seat .simultaneously with the closing of .the valve 31 in the vacuum pipe and thus admit air to .the liquid compartment 13o-permit of the liquid'flowing from the tank in the next emptying operation, and whereby downward movement of the oat will cause said -valve 43 to close simultaneously with the opening of said valve 3'! to permit of the suction from the manifold functioning in the next filling operation.

45k is -a spring loaded recoilv switch of conventional type ymounted on the-member 29 and having its operating arm 45a connected to the arm 39 whereby movement of `said .arm in a downward direction will open said switch .and movement of the arm in an upward direction will close saidswitch. A single wire 46 connected to the coil side of Athe ignition switch (not shown inthe drawings) supplies the current'to theV said switch 45.

The switch 45 is connected to the solenoid .18 by means of a Wire 4'I whereby on the turning on of the ignitionswitch, the said solenoid .will be energised andthus, when the circuit'through the switch 45 isclosed by the actuation of the float due to the presence of water in the tank, will cause a pull on the valve IB and causesame to be drawn to its outermost position and thus bring the cut 25 in said 'valve into register with the passage Illa and thus permit of the liquid flowing from the tank A through the valve into the pipe 28 and thence to the radiator. As the oat lowers in the tank inthe emptying Yoperation the arm 45a will cause the opening ofthe switch 45 and thus de-energise the coil I8, whereupon the `valve I6 will be forced, through theaction of the spring 24, tothe left `a sufficient distance to bring the valve .into the proper position to close the passages Illa and IIa during the period of operation of the engine ,as will .be described in detail hereinafter.

A casing 48 secured to the under sideV ofthe Valve casing extension I4has mounted thereina solenoid of conventional typefdesignated by the numeralg49, andthis solenoid is connected by a Wire 50 with the switch 45. s s -A plunger 5I is adapted to be actuated bythe solenoid 49 tof'an extended position through :the lowerwall voi? the extension i4 and into the path of the-valve VI5 whereby upon the movement of the said valve to the left under theinfluence of the spring 24 upon the de-energization of the solenoid. I8' due to the breaking of the connection in the switch 45 the Valve will be held in such a position as to close both-of the passages ylila and I la so that the water from the cooling system cannot be drawn into vthefauxiliary tank, r even though a vacuum is held in said tank, until the ignition fhas been shut off to de-e'nergise vthe solenoid 49 and thus permit offthe plunger receding into the casing'48 out of the path of the valve I6. "Whenv the plunger' has lmoved out. 0f the path of the valve due to the ignition having'been. turned oitl'ie said'valve is allowedto proceed to the left to the full limit,v in kwhich case the passage `Ila. isfopendorv the passage ofthe water from the engine tothe auxiliary tank; vIt is1of,ycour se obvious that if desired spring means may be emPlQYed lio moregquckly efetthe recession of the plunger. j f The plunger 5I is so positioned in relation to the valve that itbears Vagainst the under face-cf the'said valve when the .latter kis in its innermost position and is held from its extended position until the valvehasprogressed to therightsufiicientlyiar'to allow-it to enterrthe valve'casing and provide means for limiting the return move'- ment of the valve.

Where the auxiliary tank A is located below the level of the top of the radiatonmaking the return of vtheliquid to the cooling system by gravity impossible, it is necessary toy provide suitable pressure means to force-theliquid from the tank to the 'cooling system'. y This is accomplished, through the medium o f air compressing mechanism operable by the suction from theengine manifold and broadly consistsin the use of a low vacuum lifting a diaphragm ofcomparatively largearea including acoil spring which, whenrtheY vacuum isere-V leased,exerts its energy to compress sufficient air to force the water, and the `oil if desired,back into'thecOOIing system. Y s

y ln the compressing means shown herein 52 is a vcylindrical casing provided with a head 53 bolted or otherwisesecured thereto and at its lower end having a central cylindrical chamber 54 positioned partly within andk partly without theend wall 55.

A collapsible bag'or casing 56, preferably made of rubber orother suitably flexible material has its open end secured between the top end of the casing 52 and the head 5 3 .andrdepends downwardly a considerable distanceA into the said casing 52 and is provided-at its lower end `with a diaphragm 51. v Y t A coil Aspring 53 conned between the top member 59 and the diaphragm 51 provides means for influencing the collapsible member 55 towards its extended condition, v e The headA 53 provided with parallel outwardly extendingopenended Lvalve casings r59 and 68 respectively, the casing 5,9 having connection with the interiorof theengine manifold through the mediumofa pipel andthe casing, 65 havinga closure B2 threading thereover, which said closure isv provided with anA air ventv 63. v

Tee Valve gasses-5S and were, provided, with seats Gland 65 respectively, oppositely disposed in 'relation to'one another so that when. 'one valve is open the'other will be closed. Y.

Extended through the diaphragm 51 and projecting from each side thereof and adjustably secured thereto by nuts 66 is a main valve stem 6.1.

This `stem carries at its -lowerend a plungerv 68 which operateswithin the' chamber 54 and'at its top end, located within the collapsible casing 56,'has pivotal connection 4with a transversely extending toggle arm 69 which at its one' end "is pivoted to a suitable bracket 10 depending from the top member 59.

Extending upwardly from the toggle arm 69 are valve stems 1I. and 12 respectively carrying valves 13 and 14 adapted to seaton the valve seats 84 and 65. I

The valves 13 and 14 are loosely mounted on the stems and are spring pressed towards their respective seats by coil springs 15 confined-between pins 11 and the respective valves. A coil spring 18 extending lengthwise of the toggle arm 69 and connected at its ends tovsaid arm near the opposite ends of the latter provides means for Vaccentuating the vmovement of said arm towards a true horizontal position.Y

V19 is a coil spring of relatively lesser strength than the spring 58 and located between thek Ylower wall, 55 of the casing 52 and the under provided cappedy by a threaded closure '83,' which latter hasian' air inlet 84 therethrough. i f 1 A plate y85 extends across the inlet 84 'within the closure land. is yieldablyheld 'over said inlet by a spring nger 86.V

l The casing` 8| has a 'transverse partition v81 locatedl below the level'ofthe inlet 84 whereby to 'provide' between it and the end wall 88 a chamber 89. v v

- The partition 81 -has a centrally disposed outlet leading to the interior of the chamber 8 9 and .in-'this chamber is located a check valve 9| spring-held overthe opening 90 Iby means of a spring 92. 1 Y` v v `The lower end of the casing is provided with a downwardly extending nipple 93 to 'which is Asecured by means of a suitable fitting 94 apipe S5 which leads to the interior ofthe auxiliary tank A through the top wall of the latter. The operation of the inventionhereinbefore described `is as follows commencing from the stage wherein the ignition has been shut off and the Water from the radiator is in process of being drawn into vthe auxiliary tank by means of the suction in the tank created by the engine previousfto the ignition being shutoff, inwhich case the valve I6 and other elements are in the relative positions shown in Figure 2, with the valve the connection inthe switchAE Will be closedin preparation for the turning .onof `the ignition when it is desiredtozstart .the engine. AWhen the water-has all been transferred .tozthe `tank VA the ball 121 `will be held to its .seat inthe passage l la and thus seal the tank against the escape of water. The operating parts remaininthe above :recited relative positions during 'the.periodithatgtheignition is off.

When it is desired to again operate the engine the ignition is'turned onfand the engine started. This has the effect of energising the solenoids t8 and 9 with the result thatthe valve I'is instantly drawn to the right to itsfull extent whereinthe passage l la to the tank Ais closed and the cut V2l) in the valve is brought into alignment with the passage lila whereby to permit ofthe Water flowing from the said tank to the engine and radiator.

When the valve I6 in its movement to the right passes beyond the plunger the latter, due `to the inuence yof the solenoid 4S, rises intozthc valve casing and provides .a barrier to the valve on itsreturn movement, whereby to holdthe said valve to an intermediate position to close both the passages I Da and lla during the operative period ofthe engine as will be .explained-in detail hereinafter.

The reciprocal movement imparted to the valve 'I3 by lthe suction in the Ymanifold causes like movement of the air valve 'I4 and the diaphragm 51 is alternately raised andlowered through the connection between the arm 69 and the valve stem 61. This operates the plunger-E8 which compresses the air in the chamber in which said plunger operates and rforces said air outwardly through the pipe-55 and into the top of the tank A, whereby the liquid in said tank is forced outwardly and returned to the engine and radiator.

In the emptying of the tank A the float 34 lowers and when it has reached a predetermined point the connection `in the Vswitch 45 is broken and the solenoid |8'thereby vdemagnetised7 immediately upon which the spring v24 -forces the valve I6 to the left to the point Where the end of .said valve contacts the plunger 5lwhereinthe valve is located in Ysuch a position yas'to effectually close both of the passages ma and lla and thereby prevent the liquid in the cooling Asystem returning to the tank A during the operation of :the engine. The downward movement-of the float arm in the emptying of the tank A in the meantime has closed the valve 43 in the air line and hasA opened the valve 3l in the suction line preparatory ytothe next-operation of .transferring the waterfrom the coolin-g system to the'tank.

When it is desired to transfer the water tothe tank A for a period of inoperationof thegengine itis simply necessary to turn olf the ignitionv to de-energise the -solenoid 48 whereupon the plunger 5I drops out of thepath ofthe valve IB-and allows same under the inuence of Vthe spring 24 to force the valve to its extreme leftmost position to bring the cut2l into alignment with the passage yl la to permit of -the `.water -passing to the tank A under the inuenceo f the yacuum created by the engine Vbefore beingyshllt :0;1.

While the invention has beendescribedhere-in principally as relating to the transfer ofgthe'water from the cooling system of the m-achinefto the auxiliary storage tank and the return thereofit is of course understood that in the case ofgaeroplane and other air cooledengines the invention may be employed to transfer the-oilfromftne engine to the storage tank .and where both oil .and water :are Aused :as cooling agents duplicate parts/.as described hereinbefore can be provided.

As the cooling liquid 'is completely protected from the elements while it'isin .the storage tank vA it is clear that during any reasonable `period of time same Vwill retain practically al1 of itsheat with the result that .uponlitsreturn .to the engine it' will instantaneously heat the'engine parts :and thus insure-easy starting.

The invention is particularly adapted for luse in air craft, both Water and air cooled. In-the case of air cooled engines the water compartment ofthe auxiliary tank is dispensed with.

Air cooled craftthat `ily in very low temperatures vmust have their sumps drained upony landing and in order to facilitatesubsequent starting the oil may be heated before being returned'vto the crank case and this device will provide-means for accomplishing this conveniently.

In the case of water cooled high speed lighting planes sufficient time has to be allowed after starting the engine to warm the entire system'before the throttle vmay be opened with safety. They are thus earth-bound `for a considerable period. By providing a source of instantaneous heat lfor the engine system by the use of the present invention this dangerous period may be considerably shortened.

While I have illustrated and described the present preferred form of construction lfor carrying out my invention, this is capable of variation vand modification without departing from the spirit of the invention. I, therefore, do Vnot wish to be limited to the precise details of constructiongset forth, but desire to avail myself of such variations and modifications as come 4within-the scope of the appended claims.

What I claim is:

1.In an engine warming device, in combination 4with an internal combustion engine and the cooling system thereof including a radiator, an insulated liquid storage tank, a vacuum-pipe 'leading from the 'manifold of Athe engine to the interior of said tank at or near the top of the latter, a valve `casing-having aport in -eachof two substantially opposed walls and spaced liquid passages communicating with said ports, one of Vsaid ports being in communication with the lower interior of said tank, a conduit leading from the other of said ports to the radiator, acheck valve located in one of said liquid passages, a valve movable across Isaid liquid passages, said valve having two spaced circumferential grooves spaced at variance-with the vspacing of said liquid passages whereby in one position of lsaid valve-one of said circumferential grooves will be aligned with one ofsaid liquid passages only to permit of the flow of -liquidto said tank, in another position the other of said-grooves will be alignedwith the other of said liquidv passages to permit of the flow -of liquid from said tank and in Aanother position both of said liquid passages willbe closed, a float controlled by level of the liquid in said tank,` an air relief passage associated with said tank, means controlled by said oat for closing said vacuum pipe and opening saidy air relief passage simultaneously When the liquid has been transferred to said tank and opening said vacnum pipe and closing said air relief Apassage when the liquid has vbeentransferred to said cooling system, and, float controlled electrical means adapted, in the raised condition ofsaidfloat due vto the presence of liquid in Asaid tank to move said valve to closethe liquid passage in said lvalve casing to said tan-kand-to open'the liquid passage from said tank and in the lowered position of said oat holding said valve to a position wherein both of said liquid passages are closed.

2. In an engine warming device, in combination with an internal combustion engine and the cooling system thereof including a radiator, anv insulated storage tank, a vacuum pipe connecting the top of said tank with the manifold of the engine, a conduit connecting said tank with said radiator for the transfer of liquid from one to the other, a valve casing interposed in said conduit, said valve casing having parallel liquid passages communicating-at their ends with said conduit, one of said passages being for use in the flow of liquid to said tank and having a check valve therein to prevent the escapeof liquid from the tank and the other of said passages being for use in the flow of liquid from said tank, a valve movable across said liquid passages within said casing, Asaid valve having two circumferential grooves spaced at variance with the spacing of said liquid passages, said valve being spring iniluenced to a position in which the liquid passage to said tank will be open, a iloat controlled` by differences in the level of the liquid in said tank, means operable by the iloat on the emptying of the tank to open said vacuum pipe, and on'the lling of `the tank to close said vacuum pipe, an electric circuit including a circuit closer actuated by said float to a closed condition at the completion of the flow of liquid to said tank whereby on the turning on of the ignition to move said valve against the spring influence thereon to close the passage to said tank and open the passage from said tank and on the completion of the emptying of said tank actuated to an open condition whereby to release said valve, said electric circuit also including meansfor arresting the return of said valve under the spring influence at a point to close both of said liquid passages during the period the ignition is on.

3. In an engine warming device, the combination of an engine and its cooling system including av radiator, aninsulated storage tank, a vconduit connecting said tank with `said radiator for the transfer of liquid from one to the other, a rvalve casing interposed in said conduit, said valve casing having parallel liquid passages therethrough one of which is used in the ow of liquidto said tank and having a check valve seating therein to prevent the escape of liquid from the tank and the other of which passages is for the flow of liquid from said tank, a valve movable acrosssaid liquid passages, said valve having two circumferential grooves spaced at variance with the spacing of said liquid passages, spring means iniiuencing said valve to a position in which one of said circumferential grooves will be in register with the liquid passage to said tank, an electric circuit including a, solenoid adapted to actuate said valve against the influence of -said spring means to bring the other of said grooves into register with the liquid passage used inthe i'low of liquid from said tank, a circuit closer, a fioat actuated by the level of .the liquid in said tank and operating said circuit closer to energise said solenoid, electric means unaffected by the action of said circuit closer adapted upon the opening of the electric circuit and the consequent release of said Valve to arrest the movement of said valve at a point to close both of said liquid passages, a vacuum pipe connecting said tank with the manifold of the engine whereby the liquid is drawn by suction into said tank, a pressure pipe leading from the enginemanifoid to the top interior of said tank, and means interposed in said pressure pipe subject to the impulses in said manifold to compress air and force same into said tank to force the liquid from said tank into the radiator uponthe movement of said valve to a position to open the liquid passage from said tank.

4. In an engine warming device, the combination of an engine and its cooling system including a radiator, a liquid storage tank, a conduit connecting said storage tank with said radiator, a vacuum pipe connecting said tank at the top thereof with the engine manifold whereby the liquid is drawn by suction from the cooling system through said conduit, a valve interposed in said conduit, said valve having three positions, in one of which the liquid is permitted to flow lto said tank, in another of which the liquid is permitted to flow out of said tank and in another of which the said conduit is closed against the flow of vliquid to or from said tank, said valve being spring influenced to the rst mentioned position, a float adjustable through the variations of the level of the liquid in said tank, an electric circuit including a solenoid for said valve, means ractuated by said float in its movement in the absence of current in the electric circuit to close said circuit whereby on the electrifying of the circuit saidv valve will be drawn against spring influence to a position to permit liquid flowing from said tank, means actuated by said float for opening said circuit through said solenoid upon the emptying of said tank and for closing said circuit upon the filling of said tank, an air inlet to said tank,vmeans operated by said iioat adapted on the completion of the lling of said tank to close said vacuum and open said air inlet and on the emptying of said tank to open said vacuum and close said air inlet, and air compressing means operable by the suction from the engine manifold to force the liquid from said tank.

5. An engine warming device according to claim 4, in which said air compressing means comprises a main casing having a valve controlled outlet to said vacuum pipe and a valve controlled air inlet, the valves in said vacuum pipe Vand in said air inlet being oppositely directed, said casing at its lower end havingY a Valve chamber leading downwardly and communicating at its lower end with a compression chamber having a valve controlled air inlet and also having a valve controlled outlet to said tank, a collapsible air bag located within said main casing and open at its top end to said outlet to said vacuum pipe and to said air inlet, a pivoted arm having connection at points therealong with the respective stems of said valves in said vacuum pipe and said air inlet, a main valve rod `having pivotal connection at its top end with said arm to which the stems of said valves in said vacuum pipe and said air inlet are connected and extending downwardly through the lower closed end of said air bag and carrying a plunger operating in said valve chamber in the lower end of said main casing, a coiled spring within said air bag inuencing said air bag to its extended condition, and a coiled spring of relatively lesser strength than the spring in said air bag located between the lower end of said air bag and the lower end of said main casing adapted to exert upward pressure on said air bag.

GEORGE WOOD. 

